I am in the process of placing a steel roof on my model a sedan. I made roof bows out of 1 inch square tubing. What do I use between the bows and the roof skin? Silicone? I read somewhere not to weld them to the skin, so I assume I need something that can move?
I've used caulking strips between roof and bows, and it works great. Same thing the factories used in later years cars.
SEM makes a great product called "Panel Vibration Control material" SEM # 39977 designed for this exact purpose. Its not an expanding foam - some of those work too. It adheres good to properly prepped steel, will not push up your roof (witness mark where the adhesive is) and will build a large dollup and stay in shape while it is still uncured. You have time to work with it (does not cure too fast) Look 'em up on the web. Good Stuff and not too expensive. www.semproducts.com
I've seen builders use the loop side of velcro on top of the bows. It makes a good anti rattle without the adhesion of the roof to the bracing. Dave
Thanks, I wasn't sure if I want the bows stuck to the roof skin or loose? I have the skin cut to overlap the hole 1/4-1/2" and it sets decent on the bows, I didn't feel confident enough with my metal skills to cut it to fit and butt weld it. Thinking I need the skin to float on the bows while I weld the perimeter? The skin has a little crown (corvair van no ribs). I have a body shop friend recommending panel adhesive rather than welding, still torn on that idea.
A tube of 3m single component urethane swam sealer will work as will our NVH material or the flexible foam......the easy way is a the single component....everyone has a caulk gun
We have used several methods and have finally come to the conclusion some products work better than others. We only use acrylic caulk because of it's elasticity,it will allow a small amount of movement but still hold the integrity of the top metal and the bracing without any vibration. HRP
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